Interior surface pipe grinding and cleaning machine



Jan. 25, 1966 R. c. STANLEY INTERIOR SURFACE PIPE GRINDINGAND CLEANINGMACHINE Jan. 25, 1966` R. c. STANLEY INTERIOR SURFACE PIPE GRINDING ANDCLEANING MACHINE Jan. 25, 1966 R. c. STANLEY INTERIOR SURFACE PIPEGRINDING AND CLEANING MACHINE Filed Jan. 25, 1964 4 Sheets-Sheet 3INVENTOR. /f//Ae 52m/L fr BY M Arme/v5 Ys.

Jan. 25, 1966 ZZO R. c. STANLEY 3,230,668

INTERIOR SURFACE PIPE GRINDING AND CLEANING MACHINE Filed Jan. 23, 19644 Sheets-Sheet 4 g NI, INVENTOR,

N/ ///Ae SMA/fr H BY fr M M. I f Armen/EVS.

United States Patent O 3,230,668 INTERIOR SURFACE PIPE GRINDING ANDCLEANING MACHINE Richard Carl Stanley, 2602 S. 11th St., Gadsden, Ala.Filed Jan. 23, 1964, Ser. No. 339,750 11 Claims. (Cl. 551-5) Thisinvention relates to improvements in pipe cleaning machines, and moreparticularly to a machine adapted to improve the internal surface of apipe by grinding with abrasive coated belts powered by driven pressurewheels which orbit about the pipe axis so that a helical grindingpattern is generated as t-he self propelled machine proceeds through thepipe. The pitch angle of the helical grinding pattern is a function ofthe number of pressure wheels used and the width of abrasive belt. Asthe grinding operation proceeds through a pipe, compressed air isinjected ahead of the grinding belt to remove all accumulated dirt, gritand scale material. n

The fluid flow characteristics of large diameter pipes such as used inpipe lines are influenced to a large degree by the interior surfaceroughness of the pipe line. To improve this situation, many pipe lineowners are coating the interior of their pipes with various types ofpalnts or resins, a number of different methods being employed toprepare the interior surface of the pipe line to receive the paint. Mostof these methods fail by a wide margin. Some methods even aggravate theabove problem by leaving surface whiskers or splinters projecting fromthe internal surface of the pipe line.

T-he instant invention solves the above problems economically andefficiently by multiple grinding, cleaning 'and removing scale, burrs,dirt and grit from the pipe line without the additional expense ofcoating the interior o-f the pipe line.

A primary object of this invention is to provide a new internal surfacepipe grinding and cleaning machine for improving the -surface of a pipeline.

Another object of the invention is to provide a machine for helicallygrinding and cleaning the internal surface of a pipe line.

A further object of the invention is to provide an improved poweredabrasive belt grinding means for the internal surface of a pipe linewhich orbits the longitudinal axis of the pipe so that a helicalgrinding pattern is generated as the machine proceeds through the pipeline.

A still further object of the invention i-s to provide an improvedself-propelling means for an internal pipe grinding and cleaningmachine.

Another object of the invention is to provide an improved meansincluding power rotated pressure wheels which force an abrasive beltagainst the internal pipe surface and cause it -to grind and clean thesame.

A further object of the invention is to provide counterweight toeliminate the effect of centrifugal forces and gravity forces loforbiting belt grinders includ-ing spring iactuated or pneumatic cylinderactuated idler roller to tension the grinding belt so as to maintain auniform grinding pressure on all points of the internal circumferentialsurface of the pipe line as the novel machine travels forward andbackward through the same.

A still further object of the invention is to provide an electricallydriven mechanism adapted to allow passage of compressed air to removegrinding residue.

Another object of the invention is to provide a powered nonorbiting wirebrush adapted to improve the internal cleaning action of an internallongitudinal weld bead of a pipe l-ine.

Another object of the invention is to provide an improved internalsurface pipe grinding machine provided with hinged linkage means betweenthe components of 3,230,668 Patented Jan. 25, 1966 "ice the machine tofollow the internal surface contour of a curved pipe line.

A further object of the invention is to provide an irnproved internalsurface pipe grind-ing machine adapted to be adjusted to variousinternal sizes of pipe lines. l

A still further object of this invention is to provide a new internalpipe surface grinding and cleaning machine including manually controlledelectrical energy means adapted to selectively self propel the machineforwardly and backwardly in a pipe line during internal grinding andcleaning of the same.

The nature of the invention and its further advantages and features ofnovelty will become apparent to those skilled in the art from thefollowing detailed description and discussions of the exemplaryembodiment of the invention shown in the accompanying drawings wherein:

FIGURE la is a fragmentary view in elevation of the rear self-propellingportion of the machine connected to the intermediate portion or grindingmotor cage of the machine, certain hidden parts and a pipe line in whichlthe machine is operating being shown in dotted lines;

FIGURE 1b is a fragmentary sectional view in elevation of the machinetaken at the forward end of the grin-ding motor carriage showing lthepower take-off shaft, adjustable support rollers, rotary compressed airsupply means surrounding the power take-olf shaft including drive meansconnecting the power take-off shaft to a nonorbiting cleaning brushadapted to clean the internal welded seam of a p-ipe line, shown indotted line-s; p

FIGURE lc is a fragmentary sectional view in elevation of the front :endof the machine of the instant invention connected to its intermediateportion to illustrate the rotary universal joint and power shafttake-01T connections between the grinding belt head iand the front endof the supporting carriage and the rotary belt and pulley take-off ofthe propelling shaft from the grinding motor, the shaft serving as arotating conduit for the air supply and a dispensing nozzle thereforsecured to the belt head, the pipe line and certain hidden parts beingshown lin dotted lines;

FIGURE 2a is a top plan view of FIGURE 1a;

FIGURE 2b is a top plan View of FIGURE lb;

FIGURE 3 is a transverse sectional view taken substantially on line 3 3of FIGURE la in the direction of the arrows;

FIGURE 4 is a cross-sectional View of the rotary compressed `air supplygland connected to the tubular propelling shaft of FIGURE lb;

FIGURE 5 is la transverse sectional View of FIGURE lb takensubstantially on line 5 5 in the direction of the arrows;

FIGURE 6 is a transverse sectional view of FIGURE lb taken substantiallyon line 6 6 in the direction of the arrows;

FIGURE 7 is a front end elevational view of FIG- URE lc;

FIGURE 8 is an enlarged fragmentary sectional view in elevation of therotating belt head and driven roller means, spring tensioned idlers ofthe abrasive belt including an actuating counterweight thereforconnected to the belt head secured to a rotating carrier tube whichconcentrically surrounds the tubular propelling tube energized by thegrinding motor; and

FIGURE 9 is a partial sectional view of FIGURE 8 taken substantially online 9 9 in the direction of the arrows.

Referring more specifically to the drawings, in which like referencenumerals represent like parts, FIGURES la, 2a and 3 disclose the rearend of an exemplary embodiment of the new machine showing the propulsionunit mechanism 20 comprised of substantially triangular side supportframe members 21 and 22 having a pair of bottom angles 2 3 and a top barmeans 24 welded or suitably secured therebetween.

Bottom angles 23 support gear and cone drive means 25 by bolts 26.

A propelling motor 27 is supportably connected by screw bolts 28 to theback plate portion 29 of drive means 25.

A plate 30 includes a lug 31welded or suitably attached thereto and issecured by screw bolts 32 to the back portion 'of the housing of motor27. A manually operated handle or boom 33 is pivotally secured by clevis34 and bolt 35 to lug 31. Handle 33 is telescopingly secured toextension rod 34a of clevis 34 by screw bolt 36. Handle 33 terminates inahand grip 37 to which is centrally attached to an electrical Controlbox 38 having control buttons 39 and 40 for electrically energizing, bycable 41 motor 37 for forward and backward travel of the machinerespectively in a pipe line. electrically energize, by cable 45,grinding motor 46 in casing or carriage 48. Control box 38 is energizedby elec-` trical cable 47.

Propulsion wheel 50 is mounted in a rubber tire 51 of desired type tofrictionally contact the inside surface of a pipe line 52 shown inbroken lines in FIGURES la, 2a and 3. Propulsion wheel 50 is suitablymounted on axle 53 which is mounted in bearing54 vo f structural side21by a nut and washer 56 and l58, respectively. Propulsion wheel 50 issecured to sprocket 49 by bolt 55.

Gear box 25 is operatively connected by shaft 60 and nut 62 to sprocket63.

Sprocket 49 is driven by belt or chain means 65 connected to sprocket 63to drive propulsion wheel 50.

An end plate 61 of carriage 48 has an apertured coupling lug 64 weldedor suitably attached thereto and is secured by bolt 66 to motor casing48.

Propulsion unit 20 is pivotally secured by screw bolt 68 and bar 24 tolug 64 of plate 61.

The plate 61 carries an additional apertured lug 70 which -is pivotallyconnected by a bolt 72 to roller block 74 comprising side members 75 and76and Lcross member 77 welded ,or suitably connected together. Crossmember 77 threadably carries screw '78 which adjustably contacts faceplate 61 to pivot -block 74 about bolt 72.

Block 74 carries in suitable bearing bolt 80 which serves as an axle forroller 82 which contact the sides of pipe line `52h and serve -as aguiding means for the back portion of the pipe grinding `and cleaningmachine.

FIGURES 1b, 2b, 4, 5 and 6 disclose an intermediate portion of the newmachine. A flange 82a interiorly of the grinding motor carriage 48 issecured by bolt 84 to the grinding motor 46.

Carriage 48 `extends as Va circularsection 86 and flat-offset section ordeck 88. Carriage portion 86 houses a gear box 89.

Gearbox 89'is suitaby securedby-pivoted bracket 83 and adjustment screw83a to the circular side portion .of-housing 86 as best shown in FIGURE'7. Gear box 89'carries shaft 90 mounted in bearings 1 91-and 921.Afsuitable clutch 94, of a commercial type, is xed by a spline and key or other suitable means to shaft'90. The outer portion 96 of clutch 94 isintegrally attached to sprocket 98 rotatably carried on shaft 90. Shaft90 carries pulley 100 secured thereto by set screw or other suitablemeans.

Shaft 102-of motor 46 xedly carries pulley 103 thereon. Pulley 103drives pulley 100 by belt 104. Sprocket 98 drives by timing belt 101sprocket 104a carried by shaft 106. Shaft 106 is rotatably supported inbearings 108 and 110..of gear housing 89, as best shown in FIGURE 2b.

Shaft 106, shown in broken lines of FIGURE 2b iixedly carries at one enda universal joint 112 connected to shaft 113 further connected touniversal joint 114 secured to shaft llsupported by bearing 120 kin sidecarrier tube 118. The-outer end of shaft 116 has vsecured theretosprocket 122 byset screw 124.

Motor shaft 102, of FIGURE lb, is connected by uni- Control push buttonor switch .43 may be used to versal joint 126 yand intermediate shaft127 to universal joint 128 connected to tubular propelling shaft 130.

Propelling shaft 130 rotatably carries compressed air supply joint andgland 132 attached to a supply conduit 133 as hereinafter explained inconnection with FIG- URE 4.

Propelling shaft 130 xedly carries pulley 134 which drives pulley 136 bybelt 137, as shown in FIGURE 1b. Pulley 136, of FIGURES lb and 2b, issecured by set screw or other suitable means to shaft 138 of gear boxdrive means 139 of a conventional type.

Gear box drive 139 carries a transverse shaft 140 securely connected topulley 141 which drives at a desired ratio of rotation a pulley 142,carried on shaft 156, by belt 143. An abrasive roller or brush 158 isfixedly secured to shaft 156 by screw or other desired means.

Gear box drive 139 is mounted on base 144 secured by screw bolt 146 toflat deck portion 88 of housing 86 as best seen in FIGURES lb and 2b.

The flat deck portion 88 xedly supports by welding an upstanding bracket148 pivotally connected by rivet 149 to bracket 150 secured by sidesupport members 152 and 153 and bearing 154 surrounding shaft 156carrying intermediate its ends pipe seam abras-ive roller or brushcleaning 158 for cleaning the longitudinal welded seam of pipe line 52.Tensioning on belt 143 is adjusted by screw 160Q between brackets 148and 150, yas best shown in FIGURES 1b and 2b.

The front end 88a of motor housing 48 pivotally supports roller guidingside block 160 which pivotally carries by bolts 161 side roller 162which contacts the internal side surfaces of pipe line 52. Block 160 issecured internally by welded intermediate bar 163 and is furtherpivotally connected by bolt 164 to lug 1565 welded to housing 88. Roller162 are laterally adjusted by screw and bolt 165a for Contact with theinternal side surfaces of pipe line 52, as best shown in FIGURES 2b and5.

Referring more specifically to FIGURE 4, compressed air rotary gland 132is comprised generally, of gland housing body 170, bearing 171, spacer173, nut 173a, packing 174, sealing 175, packing gland 176, tubularshaft 177 secured on shaft 13.0 by collar 178, set screw 179, and O-ringseal 130. Gland body fhas an intermediate supply connection 172adaptedto be connected to the compressed air supply hose 133 shown -inFIGURE lb.

Gland body 170 is longitudinally secured on tubular shaft 177 byspring-like snap ring y 182 in recess 181 of tubular shaft 177.

Body member 170 has a recess 184 communicating with compressed airsupply connection 172 and aperture 186 communicating with the hollow airconduit 187 of power shaft 130.

For servicing ofpacking 174 and seal175, body mem-A ber 170 is securedby recessed steps 188 to end body mem-V ber 190 by screw bolt 192 asshown in `FIGURE 4.

Referring more specifically to FIGURES lb and 5, cage 88a is secured tolug 194 by bolt 195. Lug 194 is secured by bolt 196 to roller block 197comprising crossbar 198 shown in broken lines welded to lateralsidemembers 199. Pulley block 197 carries support roller 200by bolt 202.

Dead .arde l203 is fixedly secured by Welding to end housing 88a. Deadaxle 203 supports internally propelling tubular shaft 130 `by bearing204, radial support elements 204a `being provided to assist in carryingde ad axle 203.

Dead axle 203 has xed or welded thereto ring 205 which is furthersecured by bolt 206 to collar and ring ange 207. Flange 207 is securedat its lower portion to lug 208 to toggle bolt 210 which is in `turnpivotally secured to bolt 211 of block 199 to adjust supporting pulley200 to contact the various bottom internal surfaces of different sizesof pipe line 52.

As seen'in FGURES 1b and lc, seal 212 mounted in housing 218aY surroundsthe end circumferential portion of collar 207 to seal a bearing 214 inhub 215. The upper race portion of bearing 214 is pressed or suitablysecured into central hub 215 secured to carrier tube 216.

Sprocket 217 is suitably yattached by bolt 218 to hub 215.

Sprocket 122 (FIGURE 2b) by a suitable chain (not shown) drives sprocket217 to rotate carrier tube 216 carrying belt yhead 220 to generate aspiral grinding pattern on the internal surface of pipe line 52 as willbe hereinafter explained.

Referring to FIGURES lc, 7, 8 and 9, housing 215e is secured by bolts218e to central hub 215 as best seen in FIGURE 1c. Housing 215e enclosesseal 212, as shown.

FIGURE lc shows an extension of propelling tube 130, concentric deadaxle 203 and rotary concentric carrier tube 216 connected to beltgrinding head 220 and belt and pulley housing 222 connected by a drivinguniversal joint and shaft to abrasive belt grinding head 220, ashereinafter explained in detail.

Referring to FIGURES 8 and 9, abrasive belt grinding head 220 iscomprised of a central segmented spider 224 fabricated by welded plateand structural shapes of a suitable metal material welded to rotarycarrier tube 216. Each segmented spider 224 is comprised of Iplates 230and angles 231.

Platesy 230 each support four rollers 232 by standoff collar 234 :andeccentric bolt 237. Each plate 230 has welded thereto apertured lug 238.

Each energized or powered roller 240 and 240:1 is rotatably supported bya shaft 242 in bearing 243 in a U-shaped member 244 pivotally secured atthe forward end to side angle 246 by pivot bearing 248.

U-shaped member 244 is longitudinally adjusted by screw 249 :and block250 through aperture 251 in angle 246. Each outward edge portion 245 ofangle 246 is ground in a longitudinal V-shape 252 to fit the internalgroove 253 of roller 232, as best seen in FIGURES 8 and 9.

Referring to FIGURE 8, the lower angle portion 246a of angle 246 ispivotally connected by bolt 254 to rigid ot`r`-set lever 255 pivotallyconnected by bolt 257 to lever 258 further pivotally connected by bolt260 to lug 261 welded tocarrier tube 216. The off-set portion of lever255 terminates in a screw bolt 262 welded or suitably fixed theretowhich carries `a counterweight 263 held rigidly thereon by screw nutmembers 264.

Abrasive belt energizing rollers 240 and 240e carries abrasive belt 265of a desired width.

The tension on abrasive belt 265 is automatically maintained by roller266 mounted by bolt 267 in reciproeating roller block 268 mounted sideguide angle 269 welded to carrier tube 216. Spring 270 is mountedbetween roller block 268 and carrier tube 216, as best shown in FIGURE9. Spring 270 serves as a biasing means to force roller 266 against belt265 to insure that belt 265 is alwaysproperly tensioned against poweredrollers 240 `and 240e.

In use, grinding head 220 rotates with counterweight 263 and tube 216.Rollers 240 and 240:1 are heavy and their centrifugal for-ces duringtheir planetary rotation tend to throw both of these rollers and thecounterweight 263 radially outwardly simultaneously. The centrifugalforce of counterweight 263 reacts on lever 255 about fulcrum bolt 257tending to slide the mounting 252 of roller 240e radially inwardly tooppose the gravity and centrifugal forces due to the weight of therollers and their mounting, which force is radially outwardly. Byproperly adjusting the Weight of counterweight 263, its centrifugalforces are sufiicient to smooth out or eliminate the damagingcentrifugal and gravity forces of the orbiting belt grinding meansduring spiral grinding of the internal surfaces of pipe line 52 by therelative rotations of belt 265 about carrier tube 216.

Referring more specifically to FIGURES 1c and 7, belt and pulley housing222 is secured by bolts 272 to double support ring 273 suitablyfabricated from structural shapes and welded at point 274 to carriertube 216 rotatably supported on dead axle 203 by bearing 275. Endhousing ring 276 is secured by bolts 277 to the front portion ofstructural double support ring 273 to enclose air sealing 278.Propelling tube 130 i-s supported in dead axle 203 by end bearing 280.

Propelling tube 130 xedly carries pulleys 282 and 283 thereon andterminates in a rotary compressed air union 284 connected to a hose 285connected to nozzle 286 secured in holder 287 welded to pulley and belthousing 222.

Double support ring 273 carries a tube 289 welded or suitably securedtherein.

Tube 289 carries shaft means 290 and 291 in bearing 292, as best shownin FIGURE lc. Shafts 290 and 291 Carry pulleys 293 and 293e, refspectively, on one end and universal joints 294 and 294e, respectively,on the other end thereof, as best shown in FIGURE lc.

Pulley 262 drives pulley 293a by belt 296.

Pulley 283 drives lpulley 293 by belt 298.

Shaft 290 drives abrasive roller 240 by universal joints 294 and 297 andshaft 300.

Shaft 291 drives abrasive belt roller 240a by universal joints 294e and302 and shaft 303.

During operation, air is supplied to dispensing nozzle 286 throughrotary air supply joint 132, tubular propelling shaft 130, rotary airunion 234 and hose 285 connected to dispensing nozzle 286 so that aspulley housing 222 is rotated by carrier tube 216 energized by sprocket217, air nozzle 286 circumscribes the internal circumferential surfacesof pipe line 52 periodically as the inventive machine travels back andforth through the internal surfaces of the same.

During operation of the inventive machine, motor 27 energizespropul-sion wheel 50 through gear and cone drive 25, sprocket 49 and 63and chain 65 connected by sprocket 49 to traction wheel 50 toselectively propel the machine forwardly and backwardly through pipeline 52.

As the machine is propelled through pipe line 52, grinding motor 46energizes rollers 240 and 24011 by propelling shaft and differentialshaft 300 and 303. Cleaning brush 158 is rotated by pulley 134 onpropelling shaft 130. Carrier tube 216 is energized by motor shaft 102,belt 104, gear box 89, differential shaft 113 connected to shaft 116connected to sprocket 122 and by a belt (not shown) connected tosprocket 217 secured to rotary carrier tube 216 which rotates beltgrinding head 220.

A particular novelty of the new ma-chine resides in its many cooperatingmodes of operation during internal travel through pipe line 52.

To cover the full interior surface of pipe line 52, belt grinding head220 is energized by motor 46 to orbit or rotate about the pipe line axisWhile its belt rollers 240 and 240e are independently energized bypropelling tube 130 and differential shafts 300 and 303, so that ahelical grinding pattern is generated on the internal surface of thepipe line 52 as the machine proceeds through pipe line 52.

More specifically, abrasive belt grinding head 220 rotates with carriertube 216 and sprocket 217 which is energized by motor shaft 102connected by belt 104, gear box 89, shafts 113 and 120, and sprocket122.

As grinding head 220 rotates with tubular carrier shaft 216, rollers 240and 240e and abrasive belt 265 are energized by motor 46 and bypropelling tubular shaft 130 carrying pulleys 282 and 283 connected bybelts 296 and 298 to pulleys 293 and 29301, respectively, which energizerollers 240 and 240e by universal joints 294 and 297 connected by shaft300 and by universal joints 294e and 302 connected by shaft 303,respectively, as best shown in FIGURE 1c.

Belt and pulley housing 222 is secured to carrier tube 116 and rotatesin concert therewith during passage of the inventive machine throughpipe line S2.

In summary, the new machine of the present invention is reversing andself-propelling through control switches 33 and 39, cleans longitudinalseams in pipe line 52 by energized brush 158, radially grinds theinternal circumferential pipe surfaces by abrasive belt 2.65 which isalso `rotated with respect to the pipe line axis to generate a helicalgrinding pattern on the internal `surface of pipe line 52 to give amultiple cleaning and grinding eiect as air nozzle 286 and housing 222is rotated in unison with carrier tube 216 and grinding belt head 220.

From the foregoing it will now be seen that there is herein provided animproved self-propelled pipe line grinding and cleaning machine whichwill internally follow the contour of a straight or uniformly curvedpipe line and accomplishes all the objects of this invention, and othersincluding many advantages of great practical utility and commer-cialimportance.

Many and varied embodiments may be made of this inventive `concept :asobtained within the purview of this invention as desired by thoseskilled in the art without departing therefrom. Therefore, it is to beunderstood that all matter herein is to be interpreted merely asillustrative and not in a limiting sense.

I claim:

1. Apparatus for grinding and cleaning the interior surface of pipescomprising, in combination, a carriage, means for movably supportingsaid carriage interiorly of a pipe, a propulsion unit including apropulsive wheel adapted to engage a pipe interior, a motor carried bysaid propulsion unit for driving said wheel, means connecting saidpropulsion unit to said carriage at one end thereof, a second motormounted on said carriage, a dead tubular axle extending from the otherend of said carriage, a p-ower shaft universally connected to saidsecond motor concentrically mounted for rotation interiorly of said deadaxle, a carrier tube concentrically mounted for rotation exteriorly ofsaid dead axle, a belt head connected to said carrier tube, rotatableabout said dead axle, means connected to said second motor for rotatingsaid carrier tube and hence said belt head', roller drivel shaftsextending Ifrom said belt head, belt and pulley connections 4betweensaid power shaft and said roller drive shafts i-n said belt head forrotating said drive shafts independently of the rotation of said belthead, plate means carried by lsaid carrier tube, -belt rollers supportedby said plate means radially about said carrier tube, meansy connectingsaid drive shafts to said belt rollers, and an abrasive pipe cleaningVbelt extending around said belt rollers and adapted to abrasivelyengage the interior of said pipe.

2. The structure of claim 1 wherein said means connecting saidpropulsion unit to said carriage comprise a pivotal connectionpermitting lateral pivotal movement of said carriage and propulsion unitrelative to each other to facilitate the passage of the apparatusthrough uniformily curved pipes.

3. The structure of claim 2 wherein said means for introducingcompressed air into said hollow shaft includes an air sealed glandsurrounding said hollow power shaft adjacent its connection to saidsecond moto-r, said hollow shaft being rotatable in said gland, saidgland and hollow shaft having registering air openings therein and anair conduit extending to the interior of said gland.

4. The structure of claim 1 wherein said power shaft is hollow, meansare included for introducing compressed air into said hollow shaft, andan air nozzle, connected to the hollow interior of said hollow shaft, ispositioned on the outer surface of said belt head and rotatable withsaid belt head.

5. The structure of claim 1 wherein said means for movably supportingsaid carriage interiorly of a pipe include a support roller andadjusting screw means for varying the relative height of the apparatusin accordance with the diameter of the pipe in which it is adapted tooperate.

6. The structure of claim 5 wherein said means for movably supportingsaid carriage interiorly of a pipe further include guiding side rollersand adjusting means for varying the relative position of said guidingside rollers to said carriage -to center the apparatus in a pipe.

7. The structure of claim 1 wherein said iirst motor is reversible, anelongated handle extends from the end of said propulsion means remotefrom said carriage, and control means for said rst and second motors aremounted on the extending end of said handle.

8. The structure of claim 7 wherein said elongated handle comprises aplurality of telescopic section-s and means for securing said sectionsin fixed relation to each other to vary the effective length of saidhandle.

9. The structure of claim 1 wherein said belt rollers include drivenbelt rollers and idler ybelt rollers and said plate means for supportingthe belt rollers includes multiple guide means, support brackets forsaid belt rollers linearly adjustable in said guide means,- andindependent spring biasing means mounted on the guide means of saididler rollers for maintaining tension in said abrasive belt.

1?. The structure of claim 9 wherein said driven rollers are connectedby linkage to counterweigh-ts, to counteract centrifugal andgravitational forces.

1l. The structure of claim 1 wherein said carriage'includes a supportingbracket on-its upper side, an axle carried by said supporting bracket, aseam cleaning brush rotatably mounted on said axle and drive meansconnected to said power shaft `for rotating said brush.

References Cited by the Examiner UNlTED STATES PATENTS 2,305,107 12/1942Premo 5l-142 X 2,742,259 4/1956 Boucher l5-l04.l2 X 3,004,278 10/1961Stanley l5--l04-09 X ROBERT C. RIORDON, Primary Examiner.

J. SPENCER OVERHOLSER, LESTER M. SWINGLE,

Examiners.

1. APPARATUS FOR GRINDING AND CLEANING THE INTERIOR SURFACE OF PIPESCOMPRISING, IN COMBINATION, A CARRIAGE, MEANS FOR MOVABLY SUPPORTINGSAID CARRIAGE INTERIORLY OF A PIPE, A PROPULSION UNIT INCLUDING APROPULSIVE WHEEL ADAPTED TO ENGAGE A PIPE INTERIOR, A MOTOR CARRIED BYSAID PROPULSION UNIT FOR DRIVING SAID WHEEL, MEANS CONNECTING SAIDPROPULSION UNIT TO SAID CARRIAGE AT ONE END THEREOF, A SECOND MOTORMOUNTED ON SAID CARRIAGE, A DEAD TUBULAR AXLE EXTENDING FROM THE OTHEREND OF SAID CARRIAGE, A POWER SHAFT UNIVERSALLY CONNECTED TO SAID SECONDMOTOR CONCENTRICALLY MOUNTED FOR ROTATION INTERIORLY OF SAID DEAD AXLE,A CARRIER TUBE CONCENTRICALLY MOUNTED FOR ROTATION EXTERIORLY OF SAIDDEAD AXLE, A BELT HEAD CONNECTED TO SAID CARRIER TUBE, ROTATABLE ABOUTSAID DEAD AXLE, MEANS CONNECTED TO SAID SECOND MOTOR FOR ROTATING SAIDCARRIER TUBE AND HENCE SAID BELT HEAD, ROLLER DRIVE EXTENDING FROM SAIDBELT HEAD, BELT AND PULLEY CONNECTIONS BETWEEN SAID POWER SHAFT